Roger Tsien had heard the rumors for days but didn't believe them. This year's Nobel Prize in chemistry, he thought, was destined for scientists doing big, splashy work elsewhere; not for his research, which was based, in part, on the modest and poorly understood abilities of a small luminescent jellyfish.

But the rumors were true.

Yesterday, UCSD professor Tsien, 56, was awarded the 2008 Nobel in chemistry, sharing the prize with Osamu Shimomura and Martin Chalfie for their roles in discovering and developing fluorescent proteins into powerful tools that probe the behavior and interactions of molecules within cells and cells within animals.

Each of the winners will receive a one-third share of the 10 million Swedish krona prize (about $1.4 million).

“I'm completely surprised,” said Tsien, hours after receiving the 2:20 a.m. phone call from the Royal Swedish Academy of Sciences in Stockholm. “I'm not any smarter today than I was yesterday.”

But others may be. The three scientists' work “now allows researchers around the world to interrogate cells in their own environment, without harm,” said Arthur Ellis, University of California San Diego's vice chancellor for research and a chemist himself. “It's a fundamental advance of science.”

By attaching fluorescent proteins to molecules and structures inside cells, scientists can watch in real time as molecules interact, revealing functions and behaviors that have led – and will lead – to new drugs, medical therapies and a deeper understanding of life itself.

“What a wonderful choice,” said Bruce E. Bursten, president of the American Chemical Society. “This year's Nobel Prize showcases chemistry's critical but often invisible role in fostering advances in biology and medicine. Green fluorescent proteins allow scientists quite literally to see the growth of cancer and study Alzheimer's disease and other conditions that affect millions of people. This is chemistry at its very best, improving people's lives.”

UCSD researcher Roger Y. Tsien talks about sharing the 2008 Nobel Prize in Chemistry for his work on green fluorescent protein (GFP) -- and he thanks the jellyfish it came from for its contribution.<br /><a href="http://video.signonsandiego.com/vmix_hosted_apps/p/media?id=2262531&amp;item_index=4&amp;all=1&amp;sort=NULL#"><strong>View the Video</strong></a>

UCSD researcher Roger Y. Tsien talks about sharing the 2008 Nobel Prize in Chemistry for his work on green fluorescent protein (GFP) -- and he thanks the jellyfish it came from for its contribution.View the Video

SAN DIEGO'S NOBEL CONNECTIONS

Some scientists with San Diego connections who have won Nobel Prizes. Some of these were recognized for work done elsewhere.

Harold Urey, 1934, chemistry, UCSD

Francis Crick, 1962, physiology/medicine, Salk Institute

Maria Goeppert-Mayer, 1963, physics, UCSD

Robert Holley, 1968, physiology/medicine, Salk Institute

Hannes Alfven, 1970, physics, UCSD

Renato Dulbecco, 1972, physiology/medicine, Salk Institute

Gerald Edelman, 1972, physiology/medicine, Neurosciences Institute

George Emile Palade, 1974, medicine, UCSD

David Baltimore, 1975, physiology/medicine, Salk Institute

Roger Guillemin, 1977, physiology/medicine, Salk Institute

Aaron Klug, 1982, chemistry, Salk Institute

J. Michael Bishop, 1989, physiology/medicine, Salk Institute

Harry Markowitz, 1990, economics, UCSD

Kary Mullis, 1993, chemistry

Mario Molina, 1995, chemistry, UCSD

Paul Crutzen, 1995, chemistry, UCSD

K. Barry Sharpless, 2001, chemistry, Scripps Research Institute

Kurt Wuthrich, 2002, chemistry, Scripps Research Institute

Sydney Brenner, 2002, physiology/medicine, Salk Institute

Robert Engle III, 2003, economics, UCSD

Clive W.J. Granger, 2003, economics, UCSD

Roger Tsien, 2008, chemistry, UCSD

The work of Shimomura, Chalfie and Tsien encompasses much of the history and achievement in the scientific use of fluorescent proteins, or FPs.